The Diesel Stop banner

Battery problem

3364 Views 13 Replies 5 Participants Last post by  yan7gin
Hey guys, I have a 1988 f250 7.3 and my gear shifter broke off right above the transmission (zf5) so I welded it back. I removed both battery negative cables before I started. The next couple of mornings I went to start the truck and had low voltage. Like 5.3 volts on the cranking battery. So I had the alt checked and the stator came back as bad, luckily it was still under warranty so I replaced it. The next morning, same thing low voltage but this time it was .3 volts. I took the battery to Walmart to have it checked , it was less than a year old. After waiting 1hr and a half it came back good. So I get back home and check amp draw with everything off( even underhood light) and I had a 3.5 amp draw. I checked every in cab fuse one at a time with no change. I had to leave for work shortly after. As I return this weekend I bought a new voltage regulator from advance. Hooked it up and no fix, the amp draw is now dang near 5 amps. I'm needing help with this one guys. Oh and my battery light is on as well.
1 - 2 of 14 Posts
...5.3 volts on the cranking battery.
Exactly where were the meter probes when you got that reading, and what meter were you using? Are the meter's batteries good?
I took the battery to Walmart to have it checked...
That's like taking a waffle iron to IHOP to get it checked. A parts store would have been better; a dealership is usually the best. Click this & read the caption:

...check amp draw with everything off...
Again: exactly where & how did you measure this current?
...I bought a new voltage regulator from advance. Hooked it up...
Does your truck have a 1G alternator?

I would have expected it to have a 2G.

If you EVER find a problem with that alternator, I highly recommend you swap to a 130A 3G. It's nearly a bolt-on mod, even when switching from a 1G.

. . battery light is on as well.
You should start by thoroughly inspecting, cleaning, & tightening (ONLY if necessary) the battery terminals. If any are damaged, ruined, or the wrong kind, follow the instructions in this photo album to replace them:

After the batteries are fully charged (SLOWLY <5A for several hours), check idling voltage at 3 locations: across each battery, and from the alternator case to its output stud. Post the results.
See less See more
These batteries are hooked up in series...
Parallel. Connecting batteries in series ADDs their voltage; connecting them in parallel adds their AMPERAGE (or Amp-hours).
Tomorrow morning I will see what the voltage reads.
Disconnect EITHER terminal from EITHER battery (one is enough) while you measure voltage across each battery's posts.
1 - 2 of 14 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.